001/* 002 Licensed to the Apache Software Foundation (ASF) under one 003 or more contributor license agreements. See the NOTICE file 004 distributed with this work for additional information 005 regarding copyright ownership. The ASF licenses this file 006 to you under the Apache License, Version 2.0 (the 007 "License"); you may not use this file except in compliance 008 with the License. You may obtain a copy of the License at 009 010 http://www.apache.org/licenses/LICENSE-2.0 011 012 Unless required by applicable law or agreed to in writing, 013 software distributed under the License is distributed on an 014 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 KIND, either express or implied. See the License for the 016 specific language governing permissions and limitations 017 under the License. 018 */ 019 020package org.apache.wiki.filters; 021 022import org.apache.wiki.api.core.Context; 023import org.apache.wiki.api.core.Engine; 024import org.apache.wiki.api.exceptions.FilterException; 025import org.apache.wiki.api.filters.BasePageFilter; 026import org.apache.wiki.event.WikiEventListener; 027import org.apache.wiki.event.WikiEventManager; 028import org.apache.wiki.event.WikiPageEvent; 029 030import java.util.Properties; 031 032/** 033 * Fires WikiPageEvents for page events. 034 * <p> 035 * Adding a PageEventFilter to the FilterManager will automatically attach an event delegate with the WikiEventManager to provide for 036 * firing and listener management. All that remains is then adding the listener to the filter via the WikiEventManager. This is quite 037 * simple: 038 * </p> 039 * <pre> 040 * PageEventFilter filter = new PageEventFilter(); 041 * engine.getFilterManager().addPageFilter(filter,5000); 042 * // attach listener to filter 043 * WikiEventManager.addWikiEventListener(filter,listener); 044 * </pre> 045 * <p> 046 * This class provides convenience methods for adding and removing WikiEventListeners. 047 * </p> 048 * 049 * @see org.apache.wiki.event.WikiEventManager 050 */ 051public class PageEventFilter extends BasePageFilter { 052 053 /** 054 * Called whenever a new PageFilter is instantiated and reset. 055 */ 056 @Override 057 public void initialize( final Engine engine, final Properties properties ) throws FilterException { 058 super.initialize( engine, properties ); 059 } 060 061 /** 062 * This method is called whenever a page has been loaded from the provider, but not yet been sent through the TranslatorReader. 063 * Note that you cannot do HTML translation here, because TranslatorReader is likely to escape it. 064 * 065 * @param wikiContext The current wikicontext. 066 * @param content WikiMarkup. 067 */ 068 @Override 069 public String preTranslate( final Context wikiContext, final String content ) { 070 fireEvent( WikiPageEvent.PRE_TRANSLATE, wikiContext ); 071 return content; 072 } 073 074 075 /** 076 * This method is called after a page has been fed through the TranslatorReader, so anything you are seeing here is translated content. 077 * If you want to do any of your own WikiMarkup2HTML translation, do it here. 078 */ 079 @Override 080 public String postTranslate( final Context wikiContext, final String htmlContent ) { 081 fireEvent( WikiPageEvent.POST_TRANSLATE, wikiContext ); 082 return htmlContent; 083 } 084 085 086 /** 087 * This method is called before the page has been saved to the PageProvider. 088 */ 089 @Override 090 public String preSave( final Context wikiContext, final String content ) { 091 fireEvent( WikiPageEvent.PRE_SAVE, wikiContext ); 092 return content; 093 } 094 095 096 /** 097 * This method is called after the page has been successfully saved. If the saving fails for any reason, then this method will not 098 * be called. 099 * <p> 100 * Since the result is discarded from this method, this is only useful for things like counters, etc. 101 */ 102 @Override 103 public void postSave( final Context wikiContext, final String content ) { 104 fireEvent( WikiPageEvent.POST_SAVE, wikiContext ); 105 } 106 107 108 // events processing ....................................................... 109 110 /** 111 * Registers a WikiEventListener with this instance. This is a convenience method. 112 * 113 * @param listener the event listener 114 */ 115 public final synchronized void addWikiEventListener( final WikiEventListener listener ) { 116 WikiEventManager.addWikiEventListener( this, listener ); 117 } 118 119 /** 120 * Un-registers a WikiEventListener with this instance. This is a convenience method. 121 * 122 * @param listener the event listener 123 */ 124 public final synchronized void removeWikiEventListener( final WikiEventListener listener ) { 125 WikiEventManager.removeWikiEventListener( this, listener ); 126 } 127 128 /** 129 * Fires a WikiPageEvent of the provided type and page name to all registered listeners. Only <tt>PAGE_LOCK</tt> and 130 * <tt>PAGE_UNLOCK</tt> event types will fire an event; other event types are ignored. 131 * 132 * @see org.apache.wiki.event.WikiPageEvent 133 * @param type the WikiPageEvent type to be fired. 134 * @param context the WikiContext of the event. 135 */ 136 protected final void fireEvent( final int type, final Context context ) { 137 if( WikiEventManager.isListening(this ) && WikiPageEvent.isValidType( type ) ) { 138 final WikiPageEvent event = new WikiPageEvent( context.getEngine(), type, context.getPage().getName() ); 139 WikiEventManager.fireEvent(this, event ); 140 } 141 } 142 143}